The Impact of Temperature on Labor Quality: Umpire Accuracy in Major League Baseball
37 Pages Posted: 17 Jul 2019
Date Written: July 17, 2019
Using data from Major League Baseball, I compute an objective measure of the home plate umpire's work quality- the accuracy of his ball and strike calls during a game- and measure how it varies with temperature. I find that an increase in game-time temperature from between 70F and 80F to above 95F decreases an umpire's accuracy by over half a percentage point, which is about a 4% increase in the pitch-calling error rate when evaluated at the mean error rate of 15.4%. My results indicate that very hot temperatures have a nontrivial, negative effect on the labor supply quality of a highly trained and highly skilled workforce in an important, high-revenue, and high-stakes industry. I also find that temperature effects increase in severity at higher temperatures. Given that the climate is warming, these findings suggest that even greater productivity losses can be expected in the future in industries for which it is difficult to mitigate the effects of extreme heat.
Keywords: temperature, heat stress, climate change, labor quality
JEL Classification: Q54, J24
Suggested Citation: Suggested Citation